RU170230U1 - ENERGY-SAVING INSTALLATION FOR PREPARING TWO-COMPONENT SINTERING CHARGE - Google Patents

Abstract

An energy-saving installation for the preparation of a two-component sintering mixture relates to equipment for grinding raw materials and can be used in the non-ferrous, cement and other industries. The technical result in the proposed utility model is to ensure stable operation of the line under severe moisture restrictions of the intermediate and final product due to effective preliminary classification of pulp in cyclones, eliminating the useless energy consumption of grinding media for repeated, inefficient grinding of conditioned components of the charge in the mills of the second, third and fourth stages and thereby reducing the cost of electricity and grinding media for the production of the charge. This is achieved by the fact that the cyclones are installed in front of the mills of the second and fourth stages, the pressure pipelines for supplying pulp to the cyclones are equipped injectors connected to a source of compressed air, the sand pipe of each of the cyclones is connected to the loading device of the respective mill, and the drain pipe to the corresponding with a linen mixer, while the combined pulp mixer of the second stage mill is connected by a pressure pipe to the combined mixer of the third or fourth stages. Such a design of the installation allows to expand its technological capabilities, to provide effective preliminary classification of the pulp under severe moisture restrictions of the intermediate and final product, to increase the throughput mill units, transfer to the reserve up to half of the existing mills of the second, third and fourth stages without damage to the process and reduce due to this the cost of electricity and the consumption of grinding media, while the moisture content of the charge does not exceed the permissible by the technological regulations (27-28%). 1 ill.

Description

The inventive utility model relates to equipment for grinding raw materials, in particular to technological installations for the preparation of a two-component sintering mixture and can be used in non-ferrous, cement and other industries.

A known installation for the preparation of limestone-nepheline mixture, which includes two stages of grinding nepheline ore in single-chamber tube mills, the third stage of joint grinding of nepheline pulp and crushed limestone and the fourth stage of regrinding and mixing the components [Abramov V.Ya., Alekseev A.I., Badalyants Kh. .BUT. Complex processing of nepheline-apatite raw materials. M. Metallurgy, 1990, pp. 44-46]. This technological scheme was chosen due to the fact that the proportion of nepheline ore in the charge is 1.2 times greater, and the strength is 1.5-1.8 times greater than that of limestone. Requirements for the charge fed to the sintering furnace is a moisture content of not more than 30% and a grade content of -0.08 mm not less than 90%.

In the well-known multi-stage installation, working without classification of the material, the energy of grinding media is uselessly spent on repeated, inefficient grinding of conditioned components of the mixture formed in the previous stages.

The closest in technical essence is the installation for the preparation of a two-component sintering mixture (utility model patent No. 120377 IPC B02C 23/08, published on September 20, 2012), containing silos of crushed ore and limestone with feeders, tube mills of the first and subsequent stages of grinding, mill and prefabricated mixers with pumps, pulp supply pipelines, hydrocyclones installed above the mills of the second and fourth stages of grinding, while the inlet nozzles of the cyclones are connected by pressure pipelines to the prefabricated mixers stages, the sand nozzles are connected by a pipeline to the loading devices of these mills, and the mill mixer of the second stage is connected to the collecting mixer of the first stage, and the drain pipe of the cyclone of the second stage is connected through an intermediate tank to the collecting mixer of the second stage, which is connected by the pressure pipe to the loading devices of the mills of the third and the fourth stage, and the drain pipe of the cyclone of the fourth stage is connected to the mill mixer.

The well-known installation as a whole becomes inoperative under severe restrictions on the humidity of the intermediate and final product (27-28%), since the efficiency of hydrocyclones (hereinafter referred to as cyclones) is significantly reduced due to the high viscosity of the pulp. The presence of a large volume of circulating load in a closed cycle additionally significantly reduces the moisture content of the pulp while reducing the productivity of the mills for feedstock ..

The desire to restore its efficiency by increasing the moisture content of the pulp before the cyclones of the second stage mills (at least up to 42%) inevitably leads to the need to supply nepheline pulp to the loading device of the third stage mill to compensate for excess moisture with “dry” limestone, and therefore to useless energy costs for repeated, inefficient grinding of the conditioned component of the mixture formed in the previous stage.

The complexity of the hardware circuit with mills of the second stage of the known installation makes it difficult to regulate the process of classification and grinding of ore,

In addition, the installation of cyclones above the mills in the conditions of the existing production due to the presence of crane tracks becomes problematic.

The purpose of the utility model is to ensure stable operation of the line under severe moisture restrictions of the intermediate and final product due to effective preliminary classification of pulp in cyclones, eliminating the useless energy of grinding media for repeated inefficient grinding of conditioned components of the charge in mills of the second, third and fourth stages and reducing the the most cost of electricity and grinding media for the production of the charge.

This goal is achieved by the fact that cyclones are installed in front of the mills of the second and fourth stages, pressure pipelines for supplying pulp to the cyclones are equipped with injectors connected to a source of compressed air, the sand pipe of each of the cyclones is connected to the loading device of the respective mill, and the drain pipe to the corresponding mill mixer, while the combined pulp mixer of the mill of the second stage is connected by a pressure pipe to the combined mixer of the third or fourth stage ..

In FIG. 1 shows a hardware diagram of the inventive installation for the preparation of a two-component sintering mixture.

The installation for the preparation of a two-component charge contains an ore and limestone hopper with feeders (not shown in the diagram), mills 1, 2, the first and second stages of ore grinding, 3, 4, the third and fourth stages of joint grinding of limestone and ore, respectively, pipelines or trays 5 for draining the pulp from the mills by gravity, mill mixers 6 with pumps cyclones 8, installed in front of the mills of the second and fourth stages, equipped with sand 9 and drain 10 nozzles connected to the corresponding loading devices and mill th mixers, pressure pipelines 7, equipped with an injector 16, connected by a pipe 18 to a source of compressed air (not shown in the diagram), prefabricated mixers 11, 12, 13 and 14 with pumps (not shown in the diagram) while the assembly mixer 12 is connected by a pipe 17 with the assembly mixer of the charge 13 or 14 and the loading devices of the mills 1 and 3 are connected by a pressure pipe to the capacity of the circulating solution (not shown in the diagram).

Installation works as follows.

Crushed nepheline ore from the hopper by a feeder (not shown in the diagram) is loaded into the mill 1 of the first grinding stage, filled with an assortment of grinding bodies - metal balls with a diameter of 60 to 120 mm. Reverse soda solution is also fed there in a proportion that ensures optimal pulp moisture (27-28) in mill 1, and ore is minced at high gross output from the feedstock to a grade of 0.08 mm in the pulp of the class within 60-75%. The pulp from the mill 1 of the first stage of grinding by gravity is drained by pipeline or tray 5 into the mill mixer 6.

Through the pressure pipe, the pulp is fed into the collection mixer 11 and from it through the pipe 7 to the cyclone 8. At the same time, compressed air is supplied to the pipe 7 through the injector 16 through the pipe 18. A mixture of pulp with air, having a lower density and viscosity, provides acceptable classification efficiency for pulp in cyclone 8. The sands of the cyclone from the sand pipe 9 enter the loading device of the mill 2 of the second stage, from which through the pipe or tray 5 to the mill mixer 6. Conditioned product, from the drain pipe 10 of the cyclone 8, bypassing the mill 2 enters the same mixer 6 and in a mixture with re-crushed sands, is sent to the collection mixer 12. Since the moisture content of the pulp in this case remains constant (27-28%), n ephaline pulp with a sieve residue + 0.08 = 12-16%) from the collection mixer 12 through the pressure pipe 17 are sent to bypass the mill 3 into the collection mixture of the charge of the third stage 13, and with a residue on the sieve + 0.08 mm no more than 10 %, - there is an option, bypassing mills 3 and 4, to send it directly to the assembly mixer 14.

Limestone is supplied from the hopper by a feeder (not shown in the diagram) to the mill 3 of the third stage and at the same time through the pipeline a circulating solution, ensuring optimal pulp moisture in the mill 27-28%). Due to the absence of 3 conditional fine particles of nepheline pulp in the mill in this case, favorable conditions are created for grinding limestone (like ores in the mill 1) with high gross feedstock output to a grade of 0.08 mm in the pulp class within 60- 75% From the mill mixer 6 after the mill 3, the limestone pulp is fed into the collection mixer of the charge 13.

From the mixer 13, the mixture is fed through the pipeline 7 to the cyclone 8 of the fourth stage mill 4. At the same time, through the injector 16 through the pipe 18 in the pipe 7 serves compressed air. A mixture of pulp with air, having a lower density and viscosity, provides acceptable classification efficiency for pulp in cyclone 8. The sands of the cyclone through nozzle 9 enter the charging device of the fourth stage mill 4, where two materials of similar particle size are effectively co-milled in the optimum way "Cascade" mode, (with pre-loading of the mill 4 with "tsilpebs"), from which the mixture flows through the pipeline or tray 5 into the mill mixer 6. Conditioned product, from the drain pipe 10 of the cyclone 8, bypassing the mill 4 is supplied in the same mixer 6 and in admixture with a re-ground sand is sent to the mixer 14 team.

The technical result in the proposed utility model is to ensure stable operation of the line under severe moisture restrictions of the intermediate and final product due to the effective preliminary classification of pulp in cyclones, eliminating the useless use of energy of grinding media for repeated inefficient grinding of conditioned components of the charge in mills of the second, third and fourth stages and thereby reducing the cost of electricity and grinding media for the production of the charge.

This is achieved by the fact that cyclones are installed in front of the mills of the second and fourth stages, the pressure pipelines for feeding the pulp to the cyclones are equipped with injectors connected to a source of compressed air, the sand pipe of each of the cyclones is connected to the loading device of the corresponding mill, and the drain pipe to the corresponding mill mixer wherein the combined pulp mixer of the mill of the second stage is connected by a pressure pipe to the combined mixer of the charge of the third or fourth stage.

Such a design of the installation makes it possible to supply air to the pulp stream. A mixture of air with pulp has a lower density and viscosity, as a result of which conditions are created for its effective separation in cyclones 8 without excessive moisture in the pulp. After an effective preliminary classification of the pulp in cyclones 8, its conditional part (at least 50%) is sent to bypass the mills 2, 3, and 4. As a result, only a part of the pulp is fed to the mills. This increases the throughput of the mill units and allows transferring to the reserve up to half of the operating mills of the second, third and fourth stages without prejudice to the technological process and thereby reduce energy costs and the consumption of grinding media, while the moisture content of the charge does not exceed the limits allowed by the technological regulations (27-28%).

The performed experiments confirm the efficiency of the injector in combination with a compressed air source in the cyclone inlet pipe. The object of the study was nepheline ore pulp with a moisture content of 30%, with a sieve residue No. 008 = 35%. The specific goal was to establish the fact of separation of the original pulp into large and small parts when using an injector.

For this, the pulp was pumped to a hydrocyclone D = 50 mm using a pump. A pulp sample was taken from the upper discharge of the cyclone and its moisture content and sieve residue + 0.08 mm were determined. The experimental results indicate that without the use of an injector, there is no classification of pulp with a moisture content of 30%.

When using an injector, the classification of pulp of the same moisture content is quite effective (with the initial pulp with a sieve residue of 0.08 = 35%), a product with a sieve residue of + 008 = 14% is obtained in a cyclone discharge.)

Fig. one.

Claims (1)

An energy-saving installation for the preparation of a two-component sintering mixture, containing crushed ore and limestone bins with feeders, tube mills of the first and subsequent stages of grinding, mill and prefabricated mixers with pumps, pulp supply pipelines, cyclones with sand and drain pipes, characterized in that the cyclones are installed in front of the mills of the second and fourth stages, pressure pipelines for supplying pulp to cyclones are equipped with injectors connected to a source of compressed air, a sand pipe of each qi the clones are connected to the loading device of the respective mill, and the drain pipe is connected to the corresponding mill mixer, while the collecting pulp mixer of the second stage mill is connected by a pressure pipe to the collecting mixer of the third or fourth stage.

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